Government shutdown won't matter to me, the government already doesn't do what it is supposed to do.

Let's define essential services:

Essential:

Executive, Legislative, and Judicial as defined by the constitution

Non-essential

DHS
EPA
Dept of Ag
Dept of Interior
Dept of Education
Dept of Health and Human Services
Dept of Housing and Urban Development
Dept of Labor
Dept of Transportation
Dept of Energy
Dept of Veterans Affairs (roll this into the Executive Branch)
Dept of Justice